From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id E44B1900086 for ; Tue, 12 Apr 2011 20:22:31 -0400 (EDT) Received: from kpbe17.cbf.corp.google.com (kpbe17.cbf.corp.google.com [172.25.105.81]) by smtp-out.google.com with ESMTP id p3D0MPDv022259 for ; Tue, 12 Apr 2011 17:22:25 -0700 Received: from pxi2 (pxi2.prod.google.com [10.243.27.2]) by kpbe17.cbf.corp.google.com with ESMTP id p3D0MHWE007948 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Tue, 12 Apr 2011 17:22:24 -0700 Received: by pxi2 with SMTP id 2so82920pxi.24 for ; Tue, 12 Apr 2011 17:22:24 -0700 (PDT) Date: Tue, 12 Apr 2011 17:22:21 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH resend^2] mm: increase RECLAIM_DISTANCE to 30 In-Reply-To: <1302557371.7286.16607.camel@nimitz> Message-ID: References: <20110411172004.0361.A69D9226@jp.fujitsu.com> <1302557371.7286.16607.camel@nimitz> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: KOSAKI Motohiro , LKML , linux-mm , Andrew Morton , Christoph Lameter , KAMEZAWA Hiroyuki , Chris McDermott On Mon, 11 Apr 2011, Dave Hansen wrote: > > This patch raise zone_reclaim_mode threshold to 30. 30 don't have > > specific meaning. but 20 mean one-hop QPI/Hypertransport and such > > relatively cheap 2-4 socket machine are often used for tradiotional > > server as above. The intention is, their machine don't use > > zone_reclaim_mode. > > I know specifically of pieces of x86 hardware that set the information > in the BIOS to '21' *specifically* so they'll get the zone_reclaim_mode > behavior which that implies. > That doesn't seem like an argument against this patch, it's an improper configuration unless the remote memory access has a latency of 2.1x that of a local access between those two nodes. If that's the case, then it's accurately following the ACPI spec and the VM has made its policy decision to enable zone_reclaim_mode as a result. I'm surprised that they'd play with their BIOS to enable this by default, those, when it's an easily tunable sysctl. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org